'\" et
.TH ISWCTYPE "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
iswctype,
iswctype_l
\(em test character for a specified class
.SH SYNOPSIS
.LP
.nf
#include <wctype.h>
.P
int iswctype(wint_t \fIwc\fP, wctype_t \fIcharclass\fP);
int iswctype_l(wint_t \fIwc\fP, wctype_t \fIcharclass\fP,
    locale_t \fIlocale\fP);
.fi
.SH DESCRIPTION
For
\fIiswctype\fR():
The functionality described on this reference page is aligned with the
ISO\ C standard. Any conflict between the requirements described here and the
ISO\ C standard is unintentional. This volume of POSIX.1\(hy2017 defers to the ISO\ C standard.
.P
The
\fIiswctype\fR()
and
\fIiswctype_l\fR()
functions shall determine whether the wide-character code
.IR wc
has the character class
.IR charclass ,
returning true or false. The
\fIiswctype\fR()
and
\fIiswctype_l\fR()
functions are defined on WEOF and wide-character codes corresponding to
the valid character encodings in the current locale, or
in the locale represented by
.IR locale ,
respectively. If the
.IR wc
argument is not in the domain of the function, the result is undefined.
If the value of
.IR charclass
is invalid (that is, not obtained by a call to
\fIwctype\fR()
or
.IR charclass
is invalidated by a subsequent call to
\fIsetlocale\fR()
that has affected category
.IR LC_CTYPE )
the result is unspecified.
.P
The behavior is undefined if the
.IR locale
argument to
\fIiswctype_l\fR()
is the special locale object LC_GLOBAL_LOCALE or is not a valid locale
object handle.
.SH "RETURN VALUE"
The
\fIiswctype\fR()
and
\fIiswctype_l\fR()
functions shall return non-zero (true) if and only if
.IR wc
has the property described by
.IR charclass .
If
.IR charclass
is (\c
.BR wctype_t )0,
these functions shall return 0.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
.SS "Testing for a Valid Character"
.sp
.RS 4
.nf

#include <wctype.h>
\&...
int yes_or_no;
wint_t wc;
wctype_t valid_class;
\&...
if ((valid_class=wctype("vowel")) == (wctype_t)0)
    /* Invalid character class. */
yes_or_no=iswctype(wc,valid_class);
.fi
.P
.RE
.SH "APPLICATION USAGE"
The twelve strings
.BR \(dqalnum\(dq ,
.BR \(dqalpha\(dq ,
.BR \(dqblank\(dq ,
.BR \(dqcntrl\(dq ,
.BR \(dqdigit\(dq ,
.BR \(dqgraph\(dq ,
.BR \(dqlower\(dq ,
.BR \(dqprint\(dq ,
.BR \(dqpunct\(dq ,
.BR \(dqspace\(dq ,
.BR \(dqupper\(dq ,
and
.BR \(dqxdigit\(dq 
are reserved for the standard character classes. In the table below,
the functions in the left column are equivalent to the functions in the
right column.
.sp
.RS 4
.nf

iswalnum(\fIwc\fP)            iswctype(\fIwc\fP, wctype("alnum"))
iswalnum_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("alnum"), \fIlocale\fP)
iswalpha(\fIwc\fP)            iswctype(\fIwc\fP, wctype("alpha"))
iswalpha_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("alpha"), \fIlocale\fP)
iswblank(\fIwc\fP)            iswctype(\fIwc\fP, wctype("blank"))
iswblank_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("blank"), \fIlocale\fP)
iswcntrl(\fIwc\fP)            iswctype(\fIwc\fP, wctype("cntrl"))
iswcntrl_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("cntrl"), \fIlocale\fP)
iswdigit(\fIwc\fP)            iswctype(\fIwc\fP, wctype("digit"))
iswdigit_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("digit"), \fIlocale\fP)
iswgraph(\fIwc\fP)            iswctype(\fIwc\fP, wctype("graph"))
iswgraph_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("graph"), \fIlocale\fP)
iswlower(\fIwc\fP)            iswctype(\fIwc\fP, wctype("lower"))
iswlower_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("lower"), \fIlocale\fP)
iswprint(\fIwc\fP)            iswctype(\fIwc\fP, wctype("print"))
iswprint_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("print"), \fIlocale\fP)
iswpunct(\fIwc\fP)            iswctype(\fIwc\fP, wctype("punct"))
iswpunct_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("punct"), \fIlocale\fP)
iswspace(\fIwc\fP)            iswctype(\fIwc\fP, wctype("space"))
iswspace_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("space"), \fIlocale\fP)
iswupper(\fIwc\fP)            iswctype(\fIwc\fP, wctype("upper"))
iswupper_l(\fIwc\fP, \fIlocale\fP)  iswctype_l(\fIwc\fP, wctype("upper"), \fIlocale\fP)
iswxdigit(\fIwc\fP)           iswctype(\fIwc\fP, wctype("xdigit"))
iswxdigit_l(\fIwc\fP, \fIlocale\fP) iswctype_l(\fIwc\fP, wctype("xdigit"), \fIlocale\fP)
.fi
.P
.RE
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIiswalnum\fR\^(\|)",
.IR "\fIiswalpha\fR\^(\|)",
.IR "\fIiswcntrl\fR\^(\|)",
.IR "\fIiswdigit\fR\^(\|)",
.IR "\fIiswgraph\fR\^(\|)",
.IR "\fIiswlower\fR\^(\|)",
.IR "\fIiswprint\fR\^(\|)",
.IR "\fIiswpunct\fR\^(\|)",
.IR "\fIiswspace\fR\^(\|)",
.IR "\fIiswupper\fR\^(\|)",
.IR "\fIiswxdigit\fR\^(\|)",
.IR "\fIsetlocale\fR\^(\|)",
.IR "\fIuselocale\fR\^(\|)",
.IR "\fIwctype\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<locale.h>\fP",
.IR "\fB<wctype.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
